Electroencephalogram (EEG) related to music preferences can be recorded when a participant has to evaluate preference score when listening to music excerpts. Whether EEG is related to decision-making regarding music preference remains unknown. In the present study, we separated listening-to-music and evaluating-preference (thinking) periods. Participants evaluated preferences using six-point Likert scales. F3γ power during the thinking period was significantly correlated with preference. The mean discrimination rate was around 70% using F3γ power. The results suggest that F3γ power may be related to deciding music preference.